Rotary floor conditioning machine attachment

ABSTRACT

An attachment for use on a rotary floor conditioning machine comprising a master block which is integrally molded of a urethane elastomer including a centrally located hub with a circular flange member extending radially from the base thereof. A plurality of spaced vertically extending tubular receivers are carried on the circular flange. An integrally molded attachment made of urethane elastomer is provided for being attached to the master block through vertically extending posts. Stiff bristles extend out the lower surfaces of the attachment plate. The attachment plate may be molded in two stages so as to produce a stiff upper layer and a more flexible lower layer.

BACKGROUND OF THE INVENTION

Professional floor, carpet cleaning and resurfacing machines have beenin use for quite some time without much change in their purpose ofdesign. The devices normally include an electric motor which drives abrush that is, in turn, attached to the electric motor through a clutchplate. The brush is generally constructed of wood with bristlesextending out of the bottom thereof. One problem with these devices isthat as the wood deteriorates as a result of constant contact with waterand solvents used in cleaning solutions and the like. In particular, thewood weakens and deteriorates around the area where screws are insertedfor connecting the clutch plate to the brush or driving assembly. Sincea considerable amount of rotational torque is applied through the screwsthat are used for securing the clutch assembly, the clutch plate tendsto separate from the wooden brush. In an attempt to overcome thisproblem, some carpet brushes and driving assemblies have beenmanufactured from aluminum. While this reduces the problem ofdeterioration of the wood, another problem is encountered in that thenylon carpet brush bristles normally used therewith have to be attachedto the body by lacing with a thin wire which is a lengthy and timeconsuming process.

When the bristles wear out the body of the brush has to be sent back tothe manufacturer to be replaced or simply discarded. Furthermore, thealuminum main body does not have sufficient flexibility which presents aproblem when the machine is being used to condition uneven floors andsurfaces. This is especially true when the machine is a high speedrotary machine.

SUMMARY OF THE INVENTION

The invention pertains to an attachment for use on a rotary floorconditioning machine which includes a master block integrally molded ofa urethane elastomer. The master block includes a centrally located hubwhich has a circular flange member extending radially outwardly from alower portion thereof. A plurality of circumferentially spacedvertically extending tubular receivers are carried on the circularflange. Also positioned on the circular flange are circumferentiallyspaced radially extending stiffening ribs which extend from the hub tothe exterior of the circular flange. A clutch plate is secured byscrews, or any other suitable means to the hub.

The master block is designed to readily receive an attachment platewhich is integrally molded of urethane elastomer. The attachment plateincludes a circular disk which has vertically extending posts carriedthereon at locations corresponding to the locations of the tubularreceivers carried on the master block. Stiff bristles extend out thelower surface of the circular disk. The posts have a diametercorresponding to the diameter of the tubular receivers so as to producea snug connection between the posts and the tubular receivers when theposts are inserted therein for securing the attachment plate to themaster block. The properties of the urethane elastomer used forproducing the master block and the attachment plate is such that apositive gripping action is produced therebetween.

The gripping action between the posts carried on the attachment plateand the tubular receivers provided in the master block is sufficient tomaintain the master block and the attachment in contact with each otherwithout the use of securing devices such as pins or clips. Furthermore,the urethane elastomer is of such durability that it will more thanwithstand the torque imparted therethrough during scrubbing, buffing, orrefinishing of floors. In one particular embodiment nylon bristlesextend out the bottom of the circular disk and these nylon bristles arespaced sufficiently so that they will grip a scrubbing pad and the likeby merely penetrating into the porous pad.

In another embodiment, the attachment plate is molded into two layerswith short rounded nubs being integrally with the lower layer. As aresult of the attachment plate being molded in two separate layers toform an integral plate, the top layer can be made from a urethaneelastomer having less flexibility than the lower layer. Such reduceschattering during the polishing and cleaning operation since theattachment plate can flex to a certain degree.

On the lower surface of the attachment plate of still another embodimentlong soft nylon scrubbing bristles are molded integrally therewith. Thisattachment plate is normally used for scrubbing carpet.

Accordingly, it is an important object of the present invention toprovide an attachment for use on rotary floor conditioning machineswhich is very durable and strong and readily changeable.

Another important object of the present invention is to provide anattachment for use on rotary floor conditioning machines whereinunwanted oscillations are dampened during the conditioning operation bythe flexibility of the attachment plate.

Still another important object of the present invention is to provide anattachment for use on rotary floor scrubbing machines wherein scrubbingbrushes and polishing pads can be readily attached to an attachmentplate associated therewith.

Still another important object of the present invention is to provide anattachment for use on a rotary floor conditioning machine wherein asingle master block utilizing a conventional clutch plate may be usedfor several different types of attachment plates.

Other objects and advantages of this invention will become more apparentfrom a reading of the following detailed description and dependentclaims taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a perspective view illustrating a floor conditioning machineupon which an attachment constructed in accordance with the presentinvention is readily mounted.

FIG. 2 is an enlarged perspective view taken from the top illustrating amaster block forming part of the present invention.

FIG. 3 is an enlarged perspective view illustrating an attachment plateforming part of the attachment.

FIG. 4 is a perspective view taken from the bottom illustrating thebristles on one particular attachment plate.

FIG. 5 is a side elevational view illustrating the bristle configurationon still another attachment plate and

FIG. 6 is an enlarged fragmentary perspective view taken from the bottomillustrating nubs molded on the bottom of an attached plate.

DESCRIPTION OF A PREFERRED EMBODIMENT

There is illustrated in FIG. 1 a conventional floor conditioning machinesuch as a floor polisher or scrubber. The machine includes a main body10 having an electric motor mounted thereon with the handle 14 extendingupwardly therefrom for maneuvering the machine over the surface beingconditioned. Adjacent the bottom of the motor 12 is a conventionalcoupling which fits within a clutch plate that is, in turn, carried ontop of the floor conditioning attachment, broadly designated by thereference character 16. The attachment includes a master block 18 whichhas a conventional clutch plate 20 secured thereto. Positioned below themaster plate 20 is an attachment plate 22 below which a scrubbing pad 24is positioned.

Referring more particularly to FIG. 2, there is illustrated a masterblock forming part of the attachment. The master block includes acentrally located hub 26 to which the clutch plate 20 is attached bymeans of screws 28. A circular flange 30 extends radially from the lowerportion of the hub and radially extending stiffening ribs 32 extend fromadjacent the top of the hub 26 to adjacent the outer perimeter of thecircular flange 30.

A plurality of circumferentially spaced vertically extending tubularreceivers 34 are provided on the flange portion 30. The entire masterblock with the exception of the clutch plate 20 is molded of urethaneelastomer. Any suitable urethane elastomer can be utilized and oneparticular urethane elastomer is manufactured by REN Plastics and knownas REN:c:O-Thane and as a formulated polyurethane elastomer which variesfrom Shore A 40 to Shore D 70.

An attachment plate 22 is also constructed of a polyurethane elastomeris provided for readily attaching to the master block by verticallyextending posts 36. The posts have a diameter substantially equal to thediameter of the tubular receivers 34 on the master block so when theposts are inserted therein a firm grip is provided between the masterand the attachment plate.

The attachment plate 22 is normally of a larger diameter than the masterblock 18 so as to permit the overhang to flex relative to the masterblock.

As illustrated in FIG. 4 the nylon bristles 38 are molded into thecircular disk portion of the attachment plate. These bristles are spacedon the bottom surface of the plate 22 and project from the bottom of theplate 22 from 1/4 to 3/8". The purpose of the stiff nylon bristles 38 isto provide a means for securing scrubbing pads and the like to theattachment plate. Instead of using bristles such as shown in FIG. 4,nubs 40 such as shown in FIG. 6 projecting out the bottom surface of theplate 22 can be molded integrally with the plate 22 and these nubs whenpressed down on a scrubbing or polishing pad hold the scrubbing andpolishing pad securely on the machine. The nubs 40 are approximately 1/8inch in diameter and 3/16 inch long. In one embodiment the ends of thenubs 40 are rounded.

In one particular embodiment such as illustrated in FIG. 6, the urethaneelastomer plate 22 is molded in two separate layers. The upper layerwhich includes the posts 36 and indicated by the reference character 22ais more rigid than a lower layer 22b from which the nubs 40 extend. Thetwo layers 22a and 22b are adhered to each other during the moldingprocess. Since the bottom portion 22b has a Shore hardness less than thetop layer 22a, it is much more flexible than the upper layer. As aresult when the attachment plate 22 is attached to the master plate 18 asufficient torque can be transferred through the posts while allowingthe plate to flex sufficiently to be used effectively on floors that arenot perfectly flat.

As previously mentioned, one of the problems utilizing rigid attachmentplates is that oscillations and vibrations will develop in the machinewhen the machine is used on uneven surfaces. Since the attachment isconstructed of a flexible polyurethane elastomer, it will flex to acertain degree minimizing vibrations and oscillations.

In still another embodiment of the invention such as illustrated in FIG.5, the attachment plate 22 has elongated soft scrubbing nylon bristlesextending out the bottom thereof of sufficient density so that thebristles 42 are used as the scrubbing carpet without the aid of anyadditional pads. If desired, holes can be placed in the master block andattachment plate for permitting cleaning solution to pass therethrough.

It is to be understood that other suitable polymers can be used for themaster block and attachment plate instead of the polyurethane elastomer.

While a preferred embodiment of the invention has been described usingspecific terms, such description is for illustrative purposes only, andit is to be understood that changes and variations may be made withoutdeparting from the spirit or scope of the following claims.

What is claimed is:
 1. An attachment for use on a rotary floor conditioning machine comprising:a master block integrally molded of a urethane elastomer including;(i) a centrally located hub; (ii) a circular flange member extending radially from said hub having a generally planar bottom surface; and (iii) a plurality of circumferentially spaced vertically extending tubular receivers carried on said circular flange; a clutch plate secured to said hub; an attachment plate integrally molded of a urethane elastomer including;(i) a circular disk having a generally planar top surface mating with said bottom surface of said flange member; (ii) flexible torque-transmitting posts carried vertically extending on said disk at locations corresponding to the locations of said tubular receivers carried on said master block, said posts having a diameter corresponding to the diameter of said tubular receivers so as to produce a snug connection between said posts and said tubular receivers when said posts are inserted therein for securing said attachment plate to said master block and transmitting torque while allowing flexing therebetween; said circular flange member extending outwardly from a lower portion of said hub; a plurality of circumferentially spaced radially extending stiffening ribs extending between said hub and said circular flange; said circular disk including two superimposed layers of urethane elastomer material; engagement means molded into and extending out the lower layer of said two superimposed layers for penetration and securing a scrubbing or polishing pad; and said upper layer of superimposed layers being less flexible than said lower layer. 